Does the pattern (a:b) match (2+3)? Yes, as we will see below.8
Rewriting 2+3 in BDNF gives ((2,3):+). Expressing this in Lisp form gives
2+3 -> ((2,3):+) -> (: (, 2 3) (+))The arguments to the function `:' are the expressions `(, 2 3)' and `(+)'. The arguments to the function `,' are `2' and `3'.
Rewriting the pattern (a:b) in Lisp form gives
(a:b) -> (: a b)
Since both patterns are of the form (: a b), the patterns match.